AIM:To explore the effects of hepatocyte growth factor(HGF)on retinal pigment epithelium(RPE)cell behaviors.METHODS:The human adult retinal pigment epithelial cell line-19(ARPE-19)were treated by HGF or mesenchymalepi...AIM:To explore the effects of hepatocyte growth factor(HGF)on retinal pigment epithelium(RPE)cell behaviors.METHODS:The human adult retinal pigment epithelial cell line-19(ARPE-19)were treated by HGF or mesenchymalepithelial transition factor(MET)inhibitor SU11274 in vitro.Cell viability was detected by a Cell Counting Kit-8 assay.Cell proliferation and motility was detected by a bromodeoxyuridine incorporation assay and a wound healing assay,respectively.The expression levels of MET,phosphorylated MET,protein kinase B(AKT),and phosphorylated AKT proteins were determined by Western blot assay.The MET and phosphorylated MET proteins were also determined by immunofluorescence assay.RESULTS:HGF increased ARPE-19 cells’viability,proliferation and migration,and induced an increase of phosphorylated MET and phosphorylated AKT proteins.SU11274 significantly reduced cell viability,proliferation,and migration and decreased the expression of MET and AKT proteins.SU11274 suppressed HGF-induced increase of viability,proliferation,and migration in ARPE-19 cells.Additionally,SU11274 also blocked HGF-induced phosphorylation of MET and AKT proteins.CONCLUSION:HGF enhances cellular viability,proliferation,and migration in RPE cells through the MET/AKT signaling pathway,whereas this enhancement is suppressed by the MET inhibitor SU11274.HGF-induced MET/AKT signaling might be a vital contributor of RPE cells survival.展开更多
Age-related macular degeneration is a primary cause of blindness in the older adult population. Past decades of research in the pathophysiology of the disease have resulted in breakthroughs in the form of anti-vascula...Age-related macular degeneration is a primary cause of blindness in the older adult population. Past decades of research in the pathophysiology of the disease have resulted in breakthroughs in the form of anti-vascular endothelial growth factor therapies against neovascular age-related macular degeneration;however, effective treatment is not yet available for geographical atrophy in dry agerelated macular degeneration or for preventing the progression from early or mid to the late stage of age-related macular degeneration. Both clinical and experimental investigations involving human agerelated macular degeneration retinas and animal models point towards the atrophic alterations in retinal pigment epithelium as a key feature in age-related macular degeneration progression. Retinal pigment epithelium cells are primarily responsible for cellular-structural maintenance and nutrition supply to keep photoreceptors healthy and functional. The retinal pigment epithelium constantly endures a highly oxidative environment that is balanced with a cascade of antioxidant enzyme systems regulated by nuclear factor erythroid-2-related factor 2 as a main redox sensing transcription factor. Aging and accumulated oxidative stress triggers retinal pigment epithelium dysfunction and eventually death. Exposure to both environmental and genetic factors aggravates oxidative stress damage in aging retinal pigment epithelium and accelerates retinal pigment epithelium degeneration in age-related macular degeneration pathophysiology. The present review summarizes the role of oxidative stress in retinal pigment epithelium degeneration, with potential impacts from both genetic and environmental factors in age-related macular degeneration development and progression. Potential strategies to counter retinal pigment epithelium damage and protect the retinal pigment epithelium through enhancing its antioxidant capacity are also discussed, focusing on existing antioxidant nutritional supplementation, and exploring nuclear factor erythroid-2-related factor 2 and its regulators including REV-ERBα as therapeutic targets to protect against age-related macular degeneration development and progression.展开更多
Objective Age-related macular degeneration(AMD)is a degenerative retinal disease.The degeneration or death of retinal pigment epithelium(RPE)cells is implicated in the pathogenesis of AMD.This study aimed to activate ...Objective Age-related macular degeneration(AMD)is a degenerative retinal disease.The degeneration or death of retinal pigment epithelium(RPE)cells is implicated in the pathogenesis of AMD.This study aimed to activate the proliferation of RPE cells in vivo by using an adeno-associated virus(AAV)vector encodingβ-catenin to treat AMD in a mouse model.Methods Mice were intravitreally injected with AAV2/8-Y733F-VMD2-β-catenin for 2 or 4 weeks,andβ-catenin expression was measured using immunofluorescence staining,real-time quantitative reverse transcription polymerase chain reaction(PCR),and Western blotting.The function ofβ-catenin was determined using retinal flat mounts and laser-induced damage models.Finally,the safety of AAV2/8-Y733F-VMD2-β-catenin was evaluated by multiple intravitreal injections.Results AAV2/8-Y733F-VMD2-β-catenin induced the expression ofβ-catenin in RPE cells.It activated the proliferation of RPE cells and increased cyclin D1 expression.It was beneficial to the recovery of laser-induced damage by activating the proliferation of RPE cells.Furthermore,it could induce apoptosis of RPE cells by increasing the expression of Trp53,Bax and caspase3 while decreasing the expression of Bcl-2.Conclusion AAV2/8-Y733F-VMD2-β-catenin increasedβ-catenin expression in RPE cells,activated RPE cell proliferation,and helped mice heal from laser-induced eye injury.Furthermore,it could induce the apoptosis of RPE cells.Therefore,it may be a safe approach for AMD treatment.展开更多
BACKGROUND Combined hamartoma of the retina and retinal pigment epithelium(CHRRPE)is a rare congenital benign tumor which is commonly monocular.Typical CHRRPE comprises slightly raised lesions at the posterior pole,wi...BACKGROUND Combined hamartoma of the retina and retinal pigment epithelium(CHRRPE)is a rare congenital benign tumor which is commonly monocular.Typical CHRRPE comprises slightly raised lesions at the posterior pole,with proliferation membrane often leading to vascular distortion.In severe cases,macular edema,macular hole,retinal detachment or vitreous hemorrhage may occur.Patients with atypical clinical manifestations are prone to misdiagnosis by inexperienced ophthalmologists.CASE SUMMARY A 33-year-old man reported onset of right eye blurred vision for one week prior.Anterior segment and intraocular pressure were normal in both eyes.Left eye fundus photography was normal.Right eye ophthalmoscopy showed vitreous hemorrhage and off-white raised retinal lesions below the optic disc.Proliferative membranes on the lesion surfaces resulted in superficial retinal detachment and tortuosity and occlusion of peripheral blood vessels.A horseshoe-like tear in the temporal periphery was surrounded by retinal detachment.Optical coherence tomography revealed retinal thickening at the focal site with structural disturbance indicated by high reflectance.Right eye ultrasound showed retinal thickening at the lesion,stretching and uplifting of the proliferative membrane,with moderately patchy echo at the optic disc edge.Cytokines and antibodies were detected in vitreous fluids during the operation to rule out other diseases.Fundus fluorescein angiography(FFA)at postoperative follow-up led to final diagnosis of CHRRPE.CONCLUSION FFA is helpful in diagnosing retinal and retinal pigment epithelial combined hamartoma.In addition,other cytokine and etiological tests facilitate further differential diagnosis to rule out other suspected diseases.展开更多
AIM:To observe the melanin change of the retinal pigment epithelium(RPE)and choroid in the convalescent stage of Vogt-Koyanagi-Harada(VKH).METHODS:A retrospective study was performed on 40 eyes of 20 patients in the c...AIM:To observe the melanin change of the retinal pigment epithelium(RPE)and choroid in the convalescent stage of Vogt-Koyanagi-Harada(VKH).METHODS:A retrospective study was performed on 40 eyes of 20 patients in the convalescent stage of VKH.Fundus photography(FP),multi-spectral imaging(MSI),and optical coherence tomography(OCT)were performed.RESULTS:In the VKH convalescent stage,focal RPE melanin accumulation(FRMA)was detected in 34 eyes(85%)on MSI and in 7 eyes(17.5%)on FP.FRMA was limited to the previous retinal detachment area in all 28 eyes(FRMA was detected in 34 eyes on MSI,which were enrolled,and 6 eyes lacked data in the acute stage).Sunset-glow fundus was detected in 20 eyes(50%)on FP.The mean density of FRMA in a 1-mm-diameter circular area of the fovea was 0.04±0.07 on MSI,which was significantly correlated with sunset-glow fundus(ρ=0.467,P=0.02).CONCLUSION:In the VKH convalescent stage,FRMA is derived from the RPE melanin change,and sunset-glow fundus is derived from the choroid melanin change.A higher density of FRMA in the fovea and sunset-glow fundus represents more serious depigmentation of melanin.展开更多
AIM:To identify the pathological role of amyloid beta(Aβ) deposition in retinal degeneration,and explore Aβ deposition on the retinal pigment epithelium cells(RPE) layer and the associated structural and functional ...AIM:To identify the pathological role of amyloid beta(Aβ) deposition in retinal degeneration,and explore Aβ deposition on the retinal pigment epithelium cells(RPE) layer and the associated structural and functional changes in Alzheimer's disease transgenic mice.METHODS:RPE changes in the eyes of APPswe/PS1 transgenic and none transgenic(NTG) mice over 20 months old were examined.Histological changes were investigated via hematoxylin and eosin(H&E) staining and transmission electron microscopy(TEM) examination,whereas the expression of amyloid precursor protein(APP),Aβ,Zonula occludens-1(ZO-1) and Ionized calcium binding adaptor molecule-1(IBA-1) were investigated using immunohistochemistry and immunofluorescence techniques.All of the obtained results were quantitatively and statistically analyzed.RESULTS:In aged transgenic mice,an APP-positive immunoreaction and Aβ deposition were detected on the RPE layer but were undetectable in NTG mice.The RPE demonstrated some vacuole changes,shortened basal infoldings and basal deposition in histopathological examination and TEM tests,wherein irregular shapes were indicated by ZO-1 disorganization through fluorescence.Furthermore,IBA-1 positive cells were observed to have accumulated and infiltrated into the RPE layer and localized beneath the RPE/Bruch's membrane(Br M) complex,which was accompanied by an increase in BrM thickness in aged transgenic mice in comparison to NTG mice.The IBA-1 positive cells were found to be co-stained with Aβ deposition on the RPE flat mounts.CONCLUSION:The observed Aβ deposition in the RPE layer may cause RPE dysfunction,which is associated with microglia cells infiltration into the retina of aged transgenic mice,suggesting that Aβ deposition probably plays a significant role in RPE-related degenerative disease.展开更多
AIM:To investigate the effect of leucine-rich-alpha-2-glycoprotein 1(LRG1)on epithelial-mesenchymal transition(EMT)in retinal pigment epithelium(RPE)cells,and to explore the role of NADPH oxidase 4(NOX4).METHODS:RPE c...AIM:To investigate the effect of leucine-rich-alpha-2-glycoprotein 1(LRG1)on epithelial-mesenchymal transition(EMT)in retinal pigment epithelium(RPE)cells,and to explore the role of NADPH oxidase 4(NOX4).METHODS:RPE cells(ARPE-19 cell line)were treated with transforming growth factor-β1(TGF-β1)to induce EMT.Changes of the m RNA and protein expression levels of LRG1 were tested in the TGF-β1 treated cells.The recombinant human LRG1 protein(r LRG1)and si RNA of LRG1 were used to establish accumulation of exogenous LRG1 model and the down-regulation of LRG1 model in ARPE-19 cells respectively,and to detect EMT-related markers including fibronectin,α-smooth muscle actin(α-SMA)and zonula occludens-1(ZO-1).The m RNA and protein expression level of NOX4 were measured according to the above treatments.VAS2870 was used as a NOX4 inhibitor in r LRG1-treated cells.EMT-related markers were detected to verify the effect of NOX4 in the process of EMT.RESULTS:TGF-β1 promoted the expression of LRG1 at both the m RNA and protein levels during the process of EMT which showed the up-regulation of fibronectin andα-SMA,as well as the down-regulation of ZO-1.Furthermore,the r LRG1 promoted EMT of ARPE-19 cells,which manifested high levels of fibronectin andα-SMA and low level of ZO-1,whereas knockdown of LRG1 prevented EMT by decreasing the expressions of fibronectin andα-SMA and increasing the expression of ZO-1 in ARPE-19 cells.Besides,the r LRG1 activated and LRG1 si RNA suppressed NOX4 expression.EMT was inhibited when VAS2870 was used in the r LRG1-treated cells.CONCLUSION:These results for the first time demonstrate that LRG1 promotes EMT of RPE cells by activating NOX4,which may provide a novel direction to explore the mechanisms of subretinal fibrosis.展开更多
AIM:To explore the temporal mitochondrial characteristics of retinal pigment epithelium(RPE)cells obtained from human embryonic stem cells(hESC)-derived retinal organoids(hEROs-RPE),to verify the optimal period for us...AIM:To explore the temporal mitochondrial characteristics of retinal pigment epithelium(RPE)cells obtained from human embryonic stem cells(hESC)-derived retinal organoids(hEROs-RPE),to verify the optimal period for using hEROs-RPE as donor cells from the aspect of mitochondria and to optimize RPE cell-based therapeutic strategies for age-related macular degeneration(AMD).METHODS:RPE cells were obtained from hEROs and from spontaneous differentiation(SD-RPE).The mitochondrial characteristics were analyzed every 20 d from day 60 to 160.Mitochondrial quantity was measured by MitoTracker Green staining.Transmission electron microscopy(TEM)was adopted to assess the morphological features of the mitochondria,including their distribution,length,and cristae.Mitochondrial membrane potentials(MMPs)were determined by JC-1 staining and evaluated by flow cytometry,reactive oxygen species(ROS)levels were evaluated by flow cytometry,and adenosine triphosphate(ATP)levels were measured by a luminometer.Differences between two groups were analyzed by the independentsamples t-test,and comparisons among multiple groups were made using one-way ANOVA or Kruskal-Wallis H test when equal variance was not assumed.RESULTS:hEROs-RPE and SD-RPE cells from day 60 to 160 were successfully differentiated from hESCs and expressed RPE markers(Pax6,MITF,Bestrophin-1,RPE65,Cralbp).RPE features,including a cobblestonelike morphology with tight junctions(ZO-1),pigments and microvilli,were also observed in both hEROs-RPE and SDRPE cells.The mitochondrial quantities of hEROs-RPE and SD-RPE cells both peaked at day 80.However,the cristae of hEROs-RPE mitochondria were less mature and abundant than those of SD-RPE mitochondria at day 80,with hEROsRPE mitochondria becoming mature at day 100.Both hEROs-RPE and SD-RPE cells showed low ROS levels from day 100 to 140 and maintained a normal MMP during this period.However,hEROs-RPE mitochondria maintained a longer time to produce high levels of ATP(from day 120 to 140)than SD-RPE cells(only day 120).CONCLUSION:hEROs-RPE mitochondria develop more slowly and maintain a longer time to supply high-level energy than SD-RPE mitochondria.From the mitochondrial perspective,hEROs-RPE cells from day 100 to 140 are an optimal cell source for treating AMD.展开更多
Background:Cells of the retinal pigment epithelium(RPE)accumulate different kinds of granules(lipofuscin,melanolipofuscin,melanosomes)within their cell bodies,with lipofuscin and melanolipofuscin being autofluorescent...Background:Cells of the retinal pigment epithelium(RPE)accumulate different kinds of granules(lipofuscin,melanolipofuscin,melanosomes)within their cell bodies,with lipofuscin and melanolipofuscin being autofluorescent after blue light excitation.High amounts of lipofuscin granules within the RPE have been associated with the development of RPE cell death and age-related macular degeneration(AMD);however,this has not been confirmed in histology so far.Here,based on our previous dataset of RPE granule characteristics,we report the characteristics of RPE cells from human donor eyes that show either high or low numbers of intracellular granules or high or low autofluorescence(AF)intensities.Methods:RPE flatmounts of fifteen human donors were examined using high-resolution structured illumination microscopy(HR-SIM)and laser scanning microscopy(LSM).Autofluorescent granules were analyzed regarding AF phenotype and absolute number of granules.In addition,total AF intensity per cell and granule density(number of granules per cell area)were determined.For the final analysis,RPE cells with total granule number below 5th or above the 95th percentile,or a total AF intensity±1.5 standard deviations above or below the mean were included,and compared to the average RPE cell at the same location.Data are presented as mean±standard deviation.Results:Within 420 RPE cells examined,42 cells were further analyzed due to extremes regarding total granule numbers.In addition,20 RPE cells had AF 1.5 standard deviations below,28 RPE cells above the mean local AF intensity.Melanolipofuscin granules predominate in RPE cells with low granule content and low AF intensity.RPE cells with high granule content have nearly twice(1.8 times)as many granules as an average RPE cell.Conclusions:In normal eyes,outliers regarding autofluorescent granule load and AF intensity signals are rare among RPE cells,suggesting that granule deposition and subsequent AF follows intrinsic control mechanisms at a cellular level.The AF of a cell is related to the composition of intracellular granule types.Ongoing studies using AMD donor eyes will examine possible disease related changes in granule distribution and further put lipofuscin´s role in aging and AMD further into perspective.展开更多
AIM: To investigate the regulation of vascular endothelial growth factors(VEGF) and pigment epithelium-derived factor(PEDF) expression by autophagy in retinal pigment epithelium(RPE) cells on exposure to hypoxia. METH...AIM: To investigate the regulation of vascular endothelial growth factors(VEGF) and pigment epithelium-derived factor(PEDF) expression by autophagy in retinal pigment epithelium(RPE) cells on exposure to hypoxia. METHODS: ARPE-19, an RPE cell line, was treated as following: the control group was kept in a normoxic incubator; the hypoxia group was incubated in a hypoxic incubator with 1% O_2/5% CO_2/94% N_2 for 24 h; the hypoxia + 3-methyladenine(3-MA) group was pretreated with 10 mmol/L 3-MA for 1 h and then in the hypoxic incubator for 24 h; and the hypoxia + chloroquine(CQ) group was pretreated with 50 μmol/L CQ for 1 h and then in the hypoxic incubator for 24 h. The morphology and ultrastructure of the cells was observed by an inverted microscope or a transmission electronic microscope(TEM). Western blot was performed to assay the expression of autophagy-associated markers, including microtubule associated protein 1 light chain 3 B(LC3 B), Beclin-1, Atg5 and p62. The concentration of VEGF and PEDF in the culture supernatant was determined by ELISA, and the ratio of VEGF/PEDF was calculated. RESULTS: There were no obvious differences in cell morphology among different groups and autolysosomes could be observed in the cytoplasm in all groups. Compared to the control cells, the LC3 B-II/I ratio and levels of Beclin-1 and Atg5 were significantly increased and p62 level was significantly decreased in the hypoxia group. With the increase of VEGF and decrease of PEDF concentration, the VEGF/PEDF ratio was significantly increased in the hypoxia group compared to the control cells. The LC3 B-II/I ratio was significantly reduced by 3-MA treatment and increased by CQ treatment. The expressions of Beclin-1 and Atg5 were significantly reduced by 3-MA or CQ treatment, while expression of p62 was increased in the 3-MA or CQ treated cells. The concentration of VEGF was significantly decreased and PEDF increased, thereby the VEGF/PEDF ratio was decreased in the hypoxia + 3-MA group and hypoxia + CQ group compared with that in the hypoxia group. CONCLUSION: Hypoxia leads to elevated autophagy in RPE cells, and expression of VEGF and PEDF might be regulated by autophagy on exposure to hypoxia to further participate in regulating the formation of retinal neovascularization.展开更多
AIM: To evaluate the protective effects of lipoic acid-niacin(N2 L) dimers against blue light(BL)-induced oxidative damage to human retinal pigment epithelium(hRPE) cells in vitro.METHODS: h RPE cells were divided int...AIM: To evaluate the protective effects of lipoic acid-niacin(N2 L) dimers against blue light(BL)-induced oxidative damage to human retinal pigment epithelium(hRPE) cells in vitro.METHODS: h RPE cells were divided into a control group(CG), a BL group, an N2 L plus BL irradiation group, an α-lipoic acid(ALA) plus BL group, an ALA-only group, and an N2 L-only group. hRPE cellular viability was detected by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) bromide assays, and apoptosis was evaluated by annexin-V-PE/7-AAD staining followed by flow cytometry. Ultrastructural changes in subcellular organelles were observed by transmission electron microscopy. Reactive oxygen species formation was assayed by flow cytometry. The expression levels of the apoptosis-related proteins BCL-2 associated X protein(BAX), B-cell leukmia/lymphoma 2(BCL-2), and caspase-3 were quantified by Western blot analysis.RESULTS: BL exposure with a light density of 4±0.5 mW/cm2 exceeding 6 h caused hRPE toxicity, whereas treatment with a high dose of N2 L(100 mol/L) or ALA(150 mol/L) maintained cell viability at control levels. BL exposure caused vacuole-like degeneration, mitochondrial swelling, and reduced microvillus formation;however, a high dose of N2 L or ALA maintained the ultrastructure of hRPE cells and their organelles. High doses of N2 L and ALA also protected hRPE cells from BL-induced apoptosis, which was confirmed by Western blot analysis: BCL-2 expression significantly increased, while BAX and caspase-3 expression slightly decreased compared to the CG.CONCLUSION: High-dose N2 L treatment(>100 mol/L) can reduce oxidative damage in degenerating hRPE cells exposed to BL with an efficacy similar to ALA.展开更多
AIM: To investigate the effect of dopamine on bone morphogenesis protein-2(BMP-2) expression in retinal pigment epithelium(RPE) cells in vitro.METHODS: ARPE-19 cells as a human RPE cell line were cultured with dopamin...AIM: To investigate the effect of dopamine on bone morphogenesis protein-2(BMP-2) expression in retinal pigment epithelium(RPE) cells in vitro.METHODS: ARPE-19 cells as a human RPE cell line were cultured with dopamine for different times(2, 4, 6, 8, 12, 16 and 24h) or with different concentrations(0.1, 1, 2, 5, 10, 20, and 100 μg/mL) in vitro. BMP-2 m RNA expression level in ARPE-19 cells was analyzed with real-time polymerase chain reaction(PCR) analysis and BMP-2 protein level was measured with Western blot analysis. The active form of BMP-2 in the culture medium was measured with enzymelinked immunosorbent assay(ELISA).RESULTS: The expression level of BMP-2 increased significantly cultured with 20 μg/mL dopamine, at different time points(P<0.05). BMP-2 m RNA level peaked 2h and the protein level peaked at 6 and 8h after treatment. The concentrations of secreted BMP-2 elevated at 12 h and peaked at 24h(P<0.05) in a time-dependent manner. Treated with 100 μg/mL dopamine for 6h, the expression levels of BMP-2 m RNA and protein in ARPE-19 cells were enhanced significantly compared to that in the untreated cells(P<0.05). And secreted BMP-2 protein in the cell culture supernatant was also increased(P<0.05).CONCLUSION: Dopamine up-regulate BMP-2 expression in RPE cells, and this may be associated with its inhibitive effect on myopia development.展开更多
AIM: Age-related macular degeneration (AMD) is a multifactorial disease and a prevalent cause of visual impairment in developed countries. Many studies suggest that age-related maculopathy susceptibility 2 (ARMS2) is ...AIM: Age-related macular degeneration (AMD) is a multifactorial disease and a prevalent cause of visual impairment in developed countries. Many studies suggest that age-related maculopathy susceptibility 2 (ARMS2) is a second major susceptibility gene for AMD. At present, there is no functional information on this gene. Therefore, the purpose of the present study was to detect the expression of ARMS2 in retinal pigment epithelium (RPE) cells and to investigate the effect of ARMS2 on the phagocytosis function of RPE cells. · METHODS: Immunofluorescence and reverse transcriptase PCR were used to demonstrate the presence and location of ARMS2 in ARPE-19 (human retinal pigment epithelial cell line, ATCC, catalog No.CRL-2302) cells. siRNA was used to knock down ARMS2 mRNA, and the effects of the knockdown on the phagocytosis function of the ARPE-19 cells were evaluated via Fluorescence Activated Cell Sorting (FACS). · RESULTS: ARMS2 was present in ARPE-19 cells, localized in the cytosol of the perinuclear region. The expression of ARMS2 mRNA (messenger RNA) in ARPE-19 cells transfected with ARMS2-siRNA (small interfering RNA, 0.73±0.08) was decreased compared with normal cells (1.00±0.00) or with cells transfected with scrambled siRNA (0.95±0.13) (P<0.05). After incubation of RPE cells with a latex beads medium for 12, 18, or 24 hours, the fluorescence intensities were 38.04±1.02, 68.92±0.92, and 78.00±0.12 in the ARMS2-siRNA-transfected groups, respectively, and 77.98±5.43, 94.87±0.60, and 98.30±0.11 in the scrambled siRNA-transfected groups, respectively. The fluorescent intensities of the same time points in the two groups were compared using Student's t-test, and the p values were all less than 0.001 at the three different time points. · CONCLUSION: There is endogenous expression of ARMS2 in ARPE-19 cells. ARMS2 plays a role in the phagocytosis function of RPE cells, and this role may be one of the mechanisms that participates in the development of AMD.展开更多
AIM: To evaluate the thickness and volume changes of the choroidal, outer retinal layers(ORL) and retinal pigment epithelium(RPE) in patients with diabetic retinopathy(DR) using optical coherence tomography(OCT) and c...AIM: To evaluate the thickness and volume changes of the choroidal, outer retinal layers(ORL) and retinal pigment epithelium(RPE) in patients with diabetic retinopathy(DR) using optical coherence tomography(OCT) and correlate them with visual acuity.METHODS: We carried out a retrospective observational case series. Consecutive DR patients were recruited for color fundus photography and OCT assessment. The RPE, ORL and choroidal thickness were measured. The correlation with the best-corrected visual acuity(BCVA) was also investigated.RESULTS: The study included 128 eyes, comprising 45 eyes of 25 diabetic macular edema(DME) patients, 34 eyes of 20 DR without DME(non-DME) patients, and 49 eyes of 25 age-matched normal individuals. The choroidal thickness in DR patients were decreased statistically significantly compared with the control group(P<0.05). The mean macular ORL thickness in DME(73.02±15.34 μm) and non-DME groups(76.35±7.32 μm) were decreased statistically significantly compared with the control group(80.20±5.85 μm; P=0.006, P=0.013, respectively). In both the non-DME and DME groups, the RPE thickness were decreased compared with the control group(P<0.05), except in the macular and central ring. The BCVA were significant interactions with the total inner retinal volume and macular RPE thickness in the DME group(r=0.115, P<0.001, r=-0.013, P=0.017, respectively).CONCLUSION: The choroid, ORL and RPE thickness are significantly decreased in DR patients compared with controls in different segments.展开更多
AIM: To find out an animal-free, xeno-free culture method for human fetal retinal pigment epithelium(fRPE) cells aiming for cell-replacement therapy. METHODS: Human AB serum, knock-out serum replacement(KSR) and B27 w...AIM: To find out an animal-free, xeno-free culture method for human fetal retinal pigment epithelium(fRPE) cells aiming for cell-replacement therapy. METHODS: Human AB serum, knock-out serum replacement(KSR) and B27 were supplemented as a substitute of fetal bovine serum(FBS) in culture medium of human fRPE cells. Cell morphology was examined by light microscope and transmission electron microscope. Proliferation ability was detected by cell cycle analysis and examination of KI67 expression. Apoptosis was analyzed using FACS. The expression ofRPE-specific markers was demonstrated by quantitative real-time polymerase chain reaction(qPCR), Western blot(WB) and immunocytochemistry. Paracrine function was determined using enzyme-linked immunosorbent assay method.RESULTS: Our results indicated that the optimum concentration of KSR was 15%, the optimum concentration of B27 was 2%, and the optimum concentration of human AB serum was 10%. fRPE cells cultured in 15% KSR and 2% B27 media showed repressed propagation and differentiation ability, and gradually lost epithelial morphology and RPE function. While fRPE cells cultured in 10% human AB serum media showed a typical cobblestone morphology with pigmentation, elevated proliferation ability, satisfying paracrine function and expressed RPE-specific markers. CONCLUSION: Our study indicates that culturing fRPE cells in 10% human AB serum-supplemented medium is more favorable compared with KSR, B27 and traditional FBS-supplemented mediums when fRPE cells are to be applied in cell-based therapy.展开更多
AIM:To investigate the relationship between autophagy and apoptosis in photoinduced injuries in retinal pigment epithelium(RPE)cells and how Lycium barbarum polysaccharide(LBP)contributes to the increased of RPE cells...AIM:To investigate the relationship between autophagy and apoptosis in photoinduced injuries in retinal pigment epithelium(RPE)cells and how Lycium barbarum polysaccharide(LBP)contributes to the increased of RPE cells to photoinduced autophagy.METHODS:In vitro cultures of human RPE strains(ARPE-19)were prepared and randomly divided into the blank control,model,low-dose LBP,middle-dose LBP,high-dose LBP,and 3-methyladenine(3MA)groups.The viability of the RPE cells and apoptosis levels in each group were tested through cell counting kit-8(CCK8)method with a flow cytometer(Annexin V/PI double staining technique).The expression levels of LC3II,LC3I,and P62 proteins were detected with the immunofluorescence method.The expression levels of beclin1,LC3,P62,PI3K,P-mTOR,mTOR,P-Akt,and Akt proteins were tested through Western blot.RESULTS:LBP considerably strengthens cell viability and inhibits the apoptosis of RPE cells after photoinduction.The PI3K/Akt/mTOR signal pathway is activated because of the upregulation of the phosphorylation levels of Akt and mTOR proteins,and thus autophagy is inhibited.CONCLUSION:LBP can inhibit the excessive autophagy in RPE cells by activating the PI3K/Akt/mTOR signaling pathways and thereby protect RPE cells from photoinduced injuries.展开更多
Cells have intrinsic mechanisms for cleaning harmful oxidants represented mainly by reactive oxygen species (ROS). Despite the antioxidant defense, ROS can cause serious damage to the retina that with age leads to var...Cells have intrinsic mechanisms for cleaning harmful oxidants represented mainly by reactive oxygen species (ROS). Despite the antioxidant defense, ROS can cause serious damage to the retina that with age leads to various eye diseases and even blindness. Among numerous cell sites of ROS generation, mitochondrial electron transport is of crucial importance. Recently, for the purpose of cleaning ROS in the mitochondrial matrix, powerful mitochondria- targeted antioxidant “SkQ1” has been invented. We studied SkQ1 effects upon tissues of rat posterior eye cup that consisted: retinal pigment epithelium (RPE) ? choroidal coat ? scleral coat. The eye cups were isolated from the eyes of adult albino rats and cultivated in rotary tissue culture system in the presence of 20 nM SkQ1 or without this compound. After 7 days - 1 month in vitro eye cup samples were studied by immunohistochemistry, routine histology, morphometry, and digital image analysis. We have found that under chosen, “in vitro like in vivo” conditions 20 nM SkQ1 effectively reduced cell death in RPE and choroid, protected RPE from disintegration caused by cell phenotypic transformation and withdrawal from the layer, suppressed transmigration of choroidal coat cells. In the ex vivo model we used degenerative processes were more pronounced in the eye cup center where SkQ1 effect was most vivid. All this give us hopes for effectiveness of SkQ1 treatment of retinal central part that is very susceptible to light-induced over-oxidation injury and mostly suffering in many age-related diseases, AMD, in particular.展开更多
AIM:To investigate the effect of Htr A1 on the proliferation,migration and apoptosis of human retinal pigment epithelium(RPE) cells in the light injured model,as well as the expression of the apoptosis related molecul...AIM:To investigate the effect of Htr A1 on the proliferation,migration and apoptosis of human retinal pigment epithelium(RPE) cells in the light injured model,as well as the expression of the apoptosis related molecules.METHODS:The human RPE cell line ARPE-19 was exposed to blue light to establish the light injured model.The cells were transfected with Htr A1 si RNA to knockdown Htr A1 expression.Subsequent expression of Htr A1 was determined by real-time polymerase chain reaction(RTPCR) and Western blot,respectively.Changes in cell proliferation,migration and apoptosis were assessed by cell counting kit-8(CCK-8),Transwell assay and flow cytometry respectively,as well as changes in the m RNA and protein levels of Bax,Caspase-3 and Bcl-2 expression.RESULTS:Htr A1 was highly expressed in ARPE-19 cells after blue light irradiation.Knockdown of Htr A1 expression inhibited the proliferation,migration and apoptosis of the blue-light-irradiated ARPE-19 cells(P<0.05).Bax and Caspase-3 expression were significantly reduced both at m RNA and protein levels(P<0.05) after si RNA treatment.Bcl-2 expression significantly increased in blue-lightirradiated ARPE-19 cells after si RNA interference(P<0.05).CONCLUSION:Silence of Htr A1 may inhibit the proliferation,migration and apoptosis of ARPE-19 cells in light injured model.Moreover,Htr A1 suppression in blue-lightirradiated ARPE-19 cells may ameliorate cell apoptosis through down-regulation of Bax and Caspase-3,and upregulation of Bcl-2 expression.展开更多
AIM:To investigate YM155’s effect on retinal pigment epithelium(RPE)cells’viability and the potential regulatory mechanisms.METHODS:Human immortalized RPE cell lines(ARPE-19 cell line)were processed with YM155 and e...AIM:To investigate YM155’s effect on retinal pigment epithelium(RPE)cells’viability and the potential regulatory mechanisms.METHODS:Human immortalized RPE cell lines(ARPE-19 cell line)were processed with YM155 and epidermal growth factor(EGF).ARPE-19 cell viability was detected by methyl thiazolyl tetrazolium assay,and apoptosis was tested by flow cytometry assay.ARPE-19 cell proliferation was assessed with bromodeoxyuridine tagged incorporation assay,and migration ability was evaluated via a wound-healing assay.Epidermal growth factor receptor(EGFR)/MAPK pathway proteins were tested via immunoblotting.EGFR localization was examined by immunofluorescence assay.RESULTS:YM155 suppressed ARPE-19 cells’viability in a time and concentration-dependent manner.A high dose of YM155 caused a small amount of ARPE-19 cell death.YM155 significantly diminished the ARPE-19 cells’proliferative and migrative capacity.YM155 downregulated total EGFR and phosphorylated external signalregulated protein kinase(ERK),and it up-regulated the phosphorylation of P38 MAPK and c-Jun N-terminal kinase(JNK).YM155 induced endocytosis of EGFR in ARPE-19 cell.YM155 also attenuated EGF-induced ARPE-19 cells’proliferative and migrative capacity.Moreover,YM155 significantly decreased the expression of phosphorylated EGFR and ERK after treated by EGF.CONCLUSION:YM155 inhibits RPE cell survival,the cell proliferative and migrative capacity,and it effectuates a small amount of cell death through the EGFR/MAPK signaling pathway.YM155 might,therefore,be an agent to prevent and treat abnormal RPE cell survival in proliferative vitreoretinopathy.展开更多
AIM: To observe the effect of exosomes derived from human umbilical cord blood mesenchymal stem cells(h UCMSCs) on the expression of vascular endothelial growth factor-A(VEGF-A) in blue light injured human retinal pig...AIM: To observe the effect of exosomes derived from human umbilical cord blood mesenchymal stem cells(h UCMSCs) on the expression of vascular endothelial growth factor-A(VEGF-A) in blue light injured human retinal pigment epithelial(RPE) cells and laser-induced choroidal neovascularization(CNV) in rats.METHODS: Exosomes were isolated from h UCMSCs and characterized by transmission electron microscope and Western blot. MSCs-derived exosomes were cultured with RPE cells exposed to blue light. The m RNA and protein expression of VEGF-A were determined by real time-polymerase chain reaction(PCR) and Western blot, respectively. Immunofluorescence assay was used for the detection of the expression level of VEGF-A. We injected different doses of MSCs-derived exosomes intravitreally to observe and compare their effects in a mouse model of laserinduced retinal injury. The histological structure of CNV in rats was inspected by hematoxylin-eosin(HE) staining and fundus fluorescein angiography. The expression of VEGF-A was detected by immunohistochemistry.RESULTS: Exosomes exhibited the typical characteristic morphology(cup-shaped) and size(diameter between 50 and 150 nm). The exosomes marker, CD63, and h UCMSCs marker, CD90, showed a robust presence. In vitro, MSCsderived exosomes downregulated the m RNA(Exo-L: t=6.485, 7.959, 9.286; Exo-M: t=7.517, 10.170, 13.413; Exo-H: t=10.317, 12.234, 14.592, P<0.05) and protein(Exo-L: t=2.945, 4.477, 6.657; Exo-M: t=4.713, 6.421, 8.836; Exo-H:t=6.539, 12.194, 12.783; P<0.05) expression of VEGF-A in RPE cells after blue light stimulation. In vivo, we found that the MSCs-derived exosomes reduced damage, distinctly downregulated VEGF-A(Exo-H: t=0.957, 1.382; P<0.05), and gradually improved the histological structures of CNV for a better visual function(Exo-L: 0.346, Exo-M: 3.382, Exo-H: 8.571; P<0.05). CONCLUSION: MSCs-derived exosomes ameliorate blue light stimulation in RPE cells and laser-induced retinal injury via downregulation of VEGF-A.展开更多
基金the Natural Science Foundation of Shaanxi Province(No.2022JM-521)the Science and Technology Plan Project of Xi’an(No.21YXYJ0031).
文摘AIM:To explore the effects of hepatocyte growth factor(HGF)on retinal pigment epithelium(RPE)cell behaviors.METHODS:The human adult retinal pigment epithelial cell line-19(ARPE-19)were treated by HGF or mesenchymalepithelial transition factor(MET)inhibitor SU11274 in vitro.Cell viability was detected by a Cell Counting Kit-8 assay.Cell proliferation and motility was detected by a bromodeoxyuridine incorporation assay and a wound healing assay,respectively.The expression levels of MET,phosphorylated MET,protein kinase B(AKT),and phosphorylated AKT proteins were determined by Western blot assay.The MET and phosphorylated MET proteins were also determined by immunofluorescence assay.RESULTS:HGF increased ARPE-19 cells’viability,proliferation and migration,and induced an increase of phosphorylated MET and phosphorylated AKT proteins.SU11274 significantly reduced cell viability,proliferation,and migration and decreased the expression of MET and AKT proteins.SU11274 suppressed HGF-induced increase of viability,proliferation,and migration in ARPE-19 cells.Additionally,SU11274 also blocked HGF-induced phosphorylation of MET and AKT proteins.CONCLUSION:HGF enhances cellular viability,proliferation,and migration in RPE cells through the MET/AKT signaling pathway,whereas this enhancement is suppressed by the MET inhibitor SU11274.HGF-induced MET/AKT signaling might be a vital contributor of RPE cells survival.
基金supported by NIH/NEI R01 grants (EY031765,EY028100EY024963)+1 种基金BrightFocus Foundation,Research to Prevent Blindness Dolly Green Special Scholar AwardBoston Children’s Hospital Ophthalmology Foundation,Mass Lions Eye Research Fund Inc.(to JC)。
文摘Age-related macular degeneration is a primary cause of blindness in the older adult population. Past decades of research in the pathophysiology of the disease have resulted in breakthroughs in the form of anti-vascular endothelial growth factor therapies against neovascular age-related macular degeneration;however, effective treatment is not yet available for geographical atrophy in dry agerelated macular degeneration or for preventing the progression from early or mid to the late stage of age-related macular degeneration. Both clinical and experimental investigations involving human agerelated macular degeneration retinas and animal models point towards the atrophic alterations in retinal pigment epithelium as a key feature in age-related macular degeneration progression. Retinal pigment epithelium cells are primarily responsible for cellular-structural maintenance and nutrition supply to keep photoreceptors healthy and functional. The retinal pigment epithelium constantly endures a highly oxidative environment that is balanced with a cascade of antioxidant enzyme systems regulated by nuclear factor erythroid-2-related factor 2 as a main redox sensing transcription factor. Aging and accumulated oxidative stress triggers retinal pigment epithelium dysfunction and eventually death. Exposure to both environmental and genetic factors aggravates oxidative stress damage in aging retinal pigment epithelium and accelerates retinal pigment epithelium degeneration in age-related macular degeneration pathophysiology. The present review summarizes the role of oxidative stress in retinal pigment epithelium degeneration, with potential impacts from both genetic and environmental factors in age-related macular degeneration development and progression. Potential strategies to counter retinal pigment epithelium damage and protect the retinal pigment epithelium through enhancing its antioxidant capacity are also discussed, focusing on existing antioxidant nutritional supplementation, and exploring nuclear factor erythroid-2-related factor 2 and its regulators including REV-ERBα as therapeutic targets to protect against age-related macular degeneration development and progression.
基金supported by the National Natural Science Foundation of China(No.61675226).
文摘Objective Age-related macular degeneration(AMD)is a degenerative retinal disease.The degeneration or death of retinal pigment epithelium(RPE)cells is implicated in the pathogenesis of AMD.This study aimed to activate the proliferation of RPE cells in vivo by using an adeno-associated virus(AAV)vector encodingβ-catenin to treat AMD in a mouse model.Methods Mice were intravitreally injected with AAV2/8-Y733F-VMD2-β-catenin for 2 or 4 weeks,andβ-catenin expression was measured using immunofluorescence staining,real-time quantitative reverse transcription polymerase chain reaction(PCR),and Western blotting.The function ofβ-catenin was determined using retinal flat mounts and laser-induced damage models.Finally,the safety of AAV2/8-Y733F-VMD2-β-catenin was evaluated by multiple intravitreal injections.Results AAV2/8-Y733F-VMD2-β-catenin induced the expression ofβ-catenin in RPE cells.It activated the proliferation of RPE cells and increased cyclin D1 expression.It was beneficial to the recovery of laser-induced damage by activating the proliferation of RPE cells.Furthermore,it could induce apoptosis of RPE cells by increasing the expression of Trp53,Bax and caspase3 while decreasing the expression of Bcl-2.Conclusion AAV2/8-Y733F-VMD2-β-catenin increasedβ-catenin expression in RPE cells,activated RPE cell proliferation,and helped mice heal from laser-induced eye injury.Furthermore,it could induce the apoptosis of RPE cells.Therefore,it may be a safe approach for AMD treatment.
文摘BACKGROUND Combined hamartoma of the retina and retinal pigment epithelium(CHRRPE)is a rare congenital benign tumor which is commonly monocular.Typical CHRRPE comprises slightly raised lesions at the posterior pole,with proliferation membrane often leading to vascular distortion.In severe cases,macular edema,macular hole,retinal detachment or vitreous hemorrhage may occur.Patients with atypical clinical manifestations are prone to misdiagnosis by inexperienced ophthalmologists.CASE SUMMARY A 33-year-old man reported onset of right eye blurred vision for one week prior.Anterior segment and intraocular pressure were normal in both eyes.Left eye fundus photography was normal.Right eye ophthalmoscopy showed vitreous hemorrhage and off-white raised retinal lesions below the optic disc.Proliferative membranes on the lesion surfaces resulted in superficial retinal detachment and tortuosity and occlusion of peripheral blood vessels.A horseshoe-like tear in the temporal periphery was surrounded by retinal detachment.Optical coherence tomography revealed retinal thickening at the focal site with structural disturbance indicated by high reflectance.Right eye ultrasound showed retinal thickening at the lesion,stretching and uplifting of the proliferative membrane,with moderately patchy echo at the optic disc edge.Cytokines and antibodies were detected in vitreous fluids during the operation to rule out other diseases.Fundus fluorescein angiography(FFA)at postoperative follow-up led to final diagnosis of CHRRPE.CONCLUSION FFA is helpful in diagnosing retinal and retinal pigment epithelial combined hamartoma.In addition,other cytokine and etiological tests facilitate further differential diagnosis to rule out other suspected diseases.
文摘AIM:To observe the melanin change of the retinal pigment epithelium(RPE)and choroid in the convalescent stage of Vogt-Koyanagi-Harada(VKH).METHODS:A retrospective study was performed on 40 eyes of 20 patients in the convalescent stage of VKH.Fundus photography(FP),multi-spectral imaging(MSI),and optical coherence tomography(OCT)were performed.RESULTS:In the VKH convalescent stage,focal RPE melanin accumulation(FRMA)was detected in 34 eyes(85%)on MSI and in 7 eyes(17.5%)on FP.FRMA was limited to the previous retinal detachment area in all 28 eyes(FRMA was detected in 34 eyes on MSI,which were enrolled,and 6 eyes lacked data in the acute stage).Sunset-glow fundus was detected in 20 eyes(50%)on FP.The mean density of FRMA in a 1-mm-diameter circular area of the fovea was 0.04±0.07 on MSI,which was significantly correlated with sunset-glow fundus(ρ=0.467,P=0.02).CONCLUSION:In the VKH convalescent stage,FRMA is derived from the RPE melanin change,and sunset-glow fundus is derived from the choroid melanin change.A higher density of FRMA in the fovea and sunset-glow fundus represents more serious depigmentation of melanin.
基金Supported by the National Natural Science Foundation of China(No.81430009No.81400424)the Science and Technology Research and Development Project of Shaanxi Province(No.2014K11-03-07-04)
文摘AIM:To identify the pathological role of amyloid beta(Aβ) deposition in retinal degeneration,and explore Aβ deposition on the retinal pigment epithelium cells(RPE) layer and the associated structural and functional changes in Alzheimer's disease transgenic mice.METHODS:RPE changes in the eyes of APPswe/PS1 transgenic and none transgenic(NTG) mice over 20 months old were examined.Histological changes were investigated via hematoxylin and eosin(H&E) staining and transmission electron microscopy(TEM) examination,whereas the expression of amyloid precursor protein(APP),Aβ,Zonula occludens-1(ZO-1) and Ionized calcium binding adaptor molecule-1(IBA-1) were investigated using immunohistochemistry and immunofluorescence techniques.All of the obtained results were quantitatively and statistically analyzed.RESULTS:In aged transgenic mice,an APP-positive immunoreaction and Aβ deposition were detected on the RPE layer but were undetectable in NTG mice.The RPE demonstrated some vacuole changes,shortened basal infoldings and basal deposition in histopathological examination and TEM tests,wherein irregular shapes were indicated by ZO-1 disorganization through fluorescence.Furthermore,IBA-1 positive cells were observed to have accumulated and infiltrated into the RPE layer and localized beneath the RPE/Bruch's membrane(Br M) complex,which was accompanied by an increase in BrM thickness in aged transgenic mice in comparison to NTG mice.The IBA-1 positive cells were found to be co-stained with Aβ deposition on the RPE flat mounts.CONCLUSION:The observed Aβ deposition in the RPE layer may cause RPE dysfunction,which is associated with microglia cells infiltration into the retina of aged transgenic mice,suggesting that Aβ deposition probably plays a significant role in RPE-related degenerative disease.
基金Supported by the National Natural Science Foundation of China(No.81670828)the Shandong Provincial Key Research and Development Program(No.2017GSF18141)+1 种基金the Innovation Project of Shandong Academy of Medical Sciences and the National Science and Technology Major Project of China(No.2017ZX09304-010)partially supported by the Taishan Scholar Youth Professional Program(No.tspd20150215,No.tsgn20161059)。
文摘AIM:To investigate the effect of leucine-rich-alpha-2-glycoprotein 1(LRG1)on epithelial-mesenchymal transition(EMT)in retinal pigment epithelium(RPE)cells,and to explore the role of NADPH oxidase 4(NOX4).METHODS:RPE cells(ARPE-19 cell line)were treated with transforming growth factor-β1(TGF-β1)to induce EMT.Changes of the m RNA and protein expression levels of LRG1 were tested in the TGF-β1 treated cells.The recombinant human LRG1 protein(r LRG1)and si RNA of LRG1 were used to establish accumulation of exogenous LRG1 model and the down-regulation of LRG1 model in ARPE-19 cells respectively,and to detect EMT-related markers including fibronectin,α-smooth muscle actin(α-SMA)and zonula occludens-1(ZO-1).The m RNA and protein expression level of NOX4 were measured according to the above treatments.VAS2870 was used as a NOX4 inhibitor in r LRG1-treated cells.EMT-related markers were detected to verify the effect of NOX4 in the process of EMT.RESULTS:TGF-β1 promoted the expression of LRG1 at both the m RNA and protein levels during the process of EMT which showed the up-regulation of fibronectin andα-SMA,as well as the down-regulation of ZO-1.Furthermore,the r LRG1 promoted EMT of ARPE-19 cells,which manifested high levels of fibronectin andα-SMA and low level of ZO-1,whereas knockdown of LRG1 prevented EMT by decreasing the expressions of fibronectin andα-SMA and increasing the expression of ZO-1 in ARPE-19 cells.Besides,the r LRG1 activated and LRG1 si RNA suppressed NOX4 expression.EMT was inhibited when VAS2870 was used in the r LRG1-treated cells.CONCLUSION:These results for the first time demonstrate that LRG1 promotes EMT of RPE cells by activating NOX4,which may provide a novel direction to explore the mechanisms of subretinal fibrosis.
基金Supported by the National Key Research and Development Program of China(No.2018YFA01017302)the National Natural Science Foundation of China(No.82000945)。
文摘AIM:To explore the temporal mitochondrial characteristics of retinal pigment epithelium(RPE)cells obtained from human embryonic stem cells(hESC)-derived retinal organoids(hEROs-RPE),to verify the optimal period for using hEROs-RPE as donor cells from the aspect of mitochondria and to optimize RPE cell-based therapeutic strategies for age-related macular degeneration(AMD).METHODS:RPE cells were obtained from hEROs and from spontaneous differentiation(SD-RPE).The mitochondrial characteristics were analyzed every 20 d from day 60 to 160.Mitochondrial quantity was measured by MitoTracker Green staining.Transmission electron microscopy(TEM)was adopted to assess the morphological features of the mitochondria,including their distribution,length,and cristae.Mitochondrial membrane potentials(MMPs)were determined by JC-1 staining and evaluated by flow cytometry,reactive oxygen species(ROS)levels were evaluated by flow cytometry,and adenosine triphosphate(ATP)levels were measured by a luminometer.Differences between two groups were analyzed by the independentsamples t-test,and comparisons among multiple groups were made using one-way ANOVA or Kruskal-Wallis H test when equal variance was not assumed.RESULTS:hEROs-RPE and SD-RPE cells from day 60 to 160 were successfully differentiated from hESCs and expressed RPE markers(Pax6,MITF,Bestrophin-1,RPE65,Cralbp).RPE features,including a cobblestonelike morphology with tight junctions(ZO-1),pigments and microvilli,were also observed in both hEROs-RPE and SDRPE cells.The mitochondrial quantities of hEROs-RPE and SD-RPE cells both peaked at day 80.However,the cristae of hEROs-RPE mitochondria were less mature and abundant than those of SD-RPE mitochondria at day 80,with hEROsRPE mitochondria becoming mature at day 100.Both hEROs-RPE and SD-RPE cells showed low ROS levels from day 100 to 140 and maintained a normal MMP during this period.However,hEROs-RPE mitochondria maintained a longer time to produce high levels of ATP(from day 120 to 140)than SD-RPE cells(only day 120).CONCLUSION:hEROs-RPE mitochondria develop more slowly and maintain a longer time to supply high-level energy than SD-RPE mitochondria.From the mitochondrial perspective,hEROs-RPE cells from day 100 to 140 are an optimal cell source for treating AMD.
文摘Background:Cells of the retinal pigment epithelium(RPE)accumulate different kinds of granules(lipofuscin,melanolipofuscin,melanosomes)within their cell bodies,with lipofuscin and melanolipofuscin being autofluorescent after blue light excitation.High amounts of lipofuscin granules within the RPE have been associated with the development of RPE cell death and age-related macular degeneration(AMD);however,this has not been confirmed in histology so far.Here,based on our previous dataset of RPE granule characteristics,we report the characteristics of RPE cells from human donor eyes that show either high or low numbers of intracellular granules or high or low autofluorescence(AF)intensities.Methods:RPE flatmounts of fifteen human donors were examined using high-resolution structured illumination microscopy(HR-SIM)and laser scanning microscopy(LSM).Autofluorescent granules were analyzed regarding AF phenotype and absolute number of granules.In addition,total AF intensity per cell and granule density(number of granules per cell area)were determined.For the final analysis,RPE cells with total granule number below 5th or above the 95th percentile,or a total AF intensity±1.5 standard deviations above or below the mean were included,and compared to the average RPE cell at the same location.Data are presented as mean±standard deviation.Results:Within 420 RPE cells examined,42 cells were further analyzed due to extremes regarding total granule numbers.In addition,20 RPE cells had AF 1.5 standard deviations below,28 RPE cells above the mean local AF intensity.Melanolipofuscin granules predominate in RPE cells with low granule content and low AF intensity.RPE cells with high granule content have nearly twice(1.8 times)as many granules as an average RPE cell.Conclusions:In normal eyes,outliers regarding autofluorescent granule load and AF intensity signals are rare among RPE cells,suggesting that granule deposition and subsequent AF follows intrinsic control mechanisms at a cellular level.The AF of a cell is related to the composition of intracellular granule types.Ongoing studies using AMD donor eyes will examine possible disease related changes in granule distribution and further put lipofuscin´s role in aging and AMD further into perspective.
基金Supported by the National Natural Science Foundation of China(No.81500726)the Medical Research Project of Xi’an Science Technology Bureau [No.201805097YX5SF31(4)]+1 种基金the Health Research Foundation of Shaanxi Province(No.2018D074)the Outstanding Youth Talent Support Plan of Shaanxi Ordinary University
文摘AIM: To investigate the regulation of vascular endothelial growth factors(VEGF) and pigment epithelium-derived factor(PEDF) expression by autophagy in retinal pigment epithelium(RPE) cells on exposure to hypoxia. METHODS: ARPE-19, an RPE cell line, was treated as following: the control group was kept in a normoxic incubator; the hypoxia group was incubated in a hypoxic incubator with 1% O_2/5% CO_2/94% N_2 for 24 h; the hypoxia + 3-methyladenine(3-MA) group was pretreated with 10 mmol/L 3-MA for 1 h and then in the hypoxic incubator for 24 h; and the hypoxia + chloroquine(CQ) group was pretreated with 50 μmol/L CQ for 1 h and then in the hypoxic incubator for 24 h. The morphology and ultrastructure of the cells was observed by an inverted microscope or a transmission electronic microscope(TEM). Western blot was performed to assay the expression of autophagy-associated markers, including microtubule associated protein 1 light chain 3 B(LC3 B), Beclin-1, Atg5 and p62. The concentration of VEGF and PEDF in the culture supernatant was determined by ELISA, and the ratio of VEGF/PEDF was calculated. RESULTS: There were no obvious differences in cell morphology among different groups and autolysosomes could be observed in the cytoplasm in all groups. Compared to the control cells, the LC3 B-II/I ratio and levels of Beclin-1 and Atg5 were significantly increased and p62 level was significantly decreased in the hypoxia group. With the increase of VEGF and decrease of PEDF concentration, the VEGF/PEDF ratio was significantly increased in the hypoxia group compared to the control cells. The LC3 B-II/I ratio was significantly reduced by 3-MA treatment and increased by CQ treatment. The expressions of Beclin-1 and Atg5 were significantly reduced by 3-MA or CQ treatment, while expression of p62 was increased in the 3-MA or CQ treated cells. The concentration of VEGF was significantly decreased and PEDF increased, thereby the VEGF/PEDF ratio was decreased in the hypoxia + 3-MA group and hypoxia + CQ group compared with that in the hypoxia group. CONCLUSION: Hypoxia leads to elevated autophagy in RPE cells, and expression of VEGF and PEDF might be regulated by autophagy on exposure to hypoxia to further participate in regulating the formation of retinal neovascularization.
基金Supported by the Guangzhou Science and Technology Foundation of Guangdong Province (No.2014J4100035 No.2014KP000071)
文摘AIM: To evaluate the protective effects of lipoic acid-niacin(N2 L) dimers against blue light(BL)-induced oxidative damage to human retinal pigment epithelium(hRPE) cells in vitro.METHODS: h RPE cells were divided into a control group(CG), a BL group, an N2 L plus BL irradiation group, an α-lipoic acid(ALA) plus BL group, an ALA-only group, and an N2 L-only group. hRPE cellular viability was detected by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) bromide assays, and apoptosis was evaluated by annexin-V-PE/7-AAD staining followed by flow cytometry. Ultrastructural changes in subcellular organelles were observed by transmission electron microscopy. Reactive oxygen species formation was assayed by flow cytometry. The expression levels of the apoptosis-related proteins BCL-2 associated X protein(BAX), B-cell leukmia/lymphoma 2(BCL-2), and caspase-3 were quantified by Western blot analysis.RESULTS: BL exposure with a light density of 4±0.5 mW/cm2 exceeding 6 h caused hRPE toxicity, whereas treatment with a high dose of N2 L(100 mol/L) or ALA(150 mol/L) maintained cell viability at control levels. BL exposure caused vacuole-like degeneration, mitochondrial swelling, and reduced microvillus formation;however, a high dose of N2 L or ALA maintained the ultrastructure of hRPE cells and their organelles. High doses of N2 L and ALA also protected hRPE cells from BL-induced apoptosis, which was confirmed by Western blot analysis: BCL-2 expression significantly increased, while BAX and caspase-3 expression slightly decreased compared to the CG.CONCLUSION: High-dose N2 L treatment(>100 mol/L) can reduce oxidative damage in degenerating hRPE cells exposed to BL with an efficacy similar to ALA.
文摘AIM: To investigate the effect of dopamine on bone morphogenesis protein-2(BMP-2) expression in retinal pigment epithelium(RPE) cells in vitro.METHODS: ARPE-19 cells as a human RPE cell line were cultured with dopamine for different times(2, 4, 6, 8, 12, 16 and 24h) or with different concentrations(0.1, 1, 2, 5, 10, 20, and 100 μg/mL) in vitro. BMP-2 m RNA expression level in ARPE-19 cells was analyzed with real-time polymerase chain reaction(PCR) analysis and BMP-2 protein level was measured with Western blot analysis. The active form of BMP-2 in the culture medium was measured with enzymelinked immunosorbent assay(ELISA).RESULTS: The expression level of BMP-2 increased significantly cultured with 20 μg/mL dopamine, at different time points(P<0.05). BMP-2 m RNA level peaked 2h and the protein level peaked at 6 and 8h after treatment. The concentrations of secreted BMP-2 elevated at 12 h and peaked at 24h(P<0.05) in a time-dependent manner. Treated with 100 μg/mL dopamine for 6h, the expression levels of BMP-2 m RNA and protein in ARPE-19 cells were enhanced significantly compared to that in the untreated cells(P<0.05). And secreted BMP-2 protein in the cell culture supernatant was also increased(P<0.05).CONCLUSION: Dopamine up-regulate BMP-2 expression in RPE cells, and this may be associated with its inhibitive effect on myopia development.
基金Supported by National Natural Science Foundation of China(No.30901637)Qingdao Sci-Tec Bureau, China(No.08-2-1-3-nsh)
文摘AIM: Age-related macular degeneration (AMD) is a multifactorial disease and a prevalent cause of visual impairment in developed countries. Many studies suggest that age-related maculopathy susceptibility 2 (ARMS2) is a second major susceptibility gene for AMD. At present, there is no functional information on this gene. Therefore, the purpose of the present study was to detect the expression of ARMS2 in retinal pigment epithelium (RPE) cells and to investigate the effect of ARMS2 on the phagocytosis function of RPE cells. · METHODS: Immunofluorescence and reverse transcriptase PCR were used to demonstrate the presence and location of ARMS2 in ARPE-19 (human retinal pigment epithelial cell line, ATCC, catalog No.CRL-2302) cells. siRNA was used to knock down ARMS2 mRNA, and the effects of the knockdown on the phagocytosis function of the ARPE-19 cells were evaluated via Fluorescence Activated Cell Sorting (FACS). · RESULTS: ARMS2 was present in ARPE-19 cells, localized in the cytosol of the perinuclear region. The expression of ARMS2 mRNA (messenger RNA) in ARPE-19 cells transfected with ARMS2-siRNA (small interfering RNA, 0.73±0.08) was decreased compared with normal cells (1.00±0.00) or with cells transfected with scrambled siRNA (0.95±0.13) (P<0.05). After incubation of RPE cells with a latex beads medium for 12, 18, or 24 hours, the fluorescence intensities were 38.04±1.02, 68.92±0.92, and 78.00±0.12 in the ARMS2-siRNA-transfected groups, respectively, and 77.98±5.43, 94.87±0.60, and 98.30±0.11 in the scrambled siRNA-transfected groups, respectively. The fluorescent intensities of the same time points in the two groups were compared using Student's t-test, and the p values were all less than 0.001 at the three different time points. · CONCLUSION: There is endogenous expression of ARMS2 in ARPE-19 cells. ARMS2 plays a role in the phagocytosis function of RPE cells, and this role may be one of the mechanisms that participates in the development of AMD.
基金Supported by the Science and Technology Commission of Shanghai Municipality,China(No.16DZ0501100)
文摘AIM: To evaluate the thickness and volume changes of the choroidal, outer retinal layers(ORL) and retinal pigment epithelium(RPE) in patients with diabetic retinopathy(DR) using optical coherence tomography(OCT) and correlate them with visual acuity.METHODS: We carried out a retrospective observational case series. Consecutive DR patients were recruited for color fundus photography and OCT assessment. The RPE, ORL and choroidal thickness were measured. The correlation with the best-corrected visual acuity(BCVA) was also investigated.RESULTS: The study included 128 eyes, comprising 45 eyes of 25 diabetic macular edema(DME) patients, 34 eyes of 20 DR without DME(non-DME) patients, and 49 eyes of 25 age-matched normal individuals. The choroidal thickness in DR patients were decreased statistically significantly compared with the control group(P<0.05). The mean macular ORL thickness in DME(73.02±15.34 μm) and non-DME groups(76.35±7.32 μm) were decreased statistically significantly compared with the control group(80.20±5.85 μm; P=0.006, P=0.013, respectively). In both the non-DME and DME groups, the RPE thickness were decreased compared with the control group(P<0.05), except in the macular and central ring. The BCVA were significant interactions with the total inner retinal volume and macular RPE thickness in the DME group(r=0.115, P<0.001, r=-0.013, P=0.017, respectively).CONCLUSION: The choroid, ORL and RPE thickness are significantly decreased in DR patients compared with controls in different segments.
基金Supported by National Key Research and Development Program of China(No.2017YFA0104101)
文摘AIM: To find out an animal-free, xeno-free culture method for human fetal retinal pigment epithelium(fRPE) cells aiming for cell-replacement therapy. METHODS: Human AB serum, knock-out serum replacement(KSR) and B27 were supplemented as a substitute of fetal bovine serum(FBS) in culture medium of human fRPE cells. Cell morphology was examined by light microscope and transmission electron microscope. Proliferation ability was detected by cell cycle analysis and examination of KI67 expression. Apoptosis was analyzed using FACS. The expression ofRPE-specific markers was demonstrated by quantitative real-time polymerase chain reaction(qPCR), Western blot(WB) and immunocytochemistry. Paracrine function was determined using enzyme-linked immunosorbent assay method.RESULTS: Our results indicated that the optimum concentration of KSR was 15%, the optimum concentration of B27 was 2%, and the optimum concentration of human AB serum was 10%. fRPE cells cultured in 15% KSR and 2% B27 media showed repressed propagation and differentiation ability, and gradually lost epithelial morphology and RPE function. While fRPE cells cultured in 10% human AB serum media showed a typical cobblestone morphology with pigmentation, elevated proliferation ability, satisfying paracrine function and expressed RPE-specific markers. CONCLUSION: Our study indicates that culturing fRPE cells in 10% human AB serum-supplemented medium is more favorable compared with KSR, B27 and traditional FBS-supplemented mediums when fRPE cells are to be applied in cell-based therapy.
基金Supported by National Natural Science Foundation of China(No.82060885)Ningxia Scientific Research Program for Institution of Higher Education(No.NGY2018-99)Ningxia Natural Science Foundation(No.2020AAC03172)。
文摘AIM:To investigate the relationship between autophagy and apoptosis in photoinduced injuries in retinal pigment epithelium(RPE)cells and how Lycium barbarum polysaccharide(LBP)contributes to the increased of RPE cells to photoinduced autophagy.METHODS:In vitro cultures of human RPE strains(ARPE-19)were prepared and randomly divided into the blank control,model,low-dose LBP,middle-dose LBP,high-dose LBP,and 3-methyladenine(3MA)groups.The viability of the RPE cells and apoptosis levels in each group were tested through cell counting kit-8(CCK8)method with a flow cytometer(Annexin V/PI double staining technique).The expression levels of LC3II,LC3I,and P62 proteins were detected with the immunofluorescence method.The expression levels of beclin1,LC3,P62,PI3K,P-mTOR,mTOR,P-Akt,and Akt proteins were tested through Western blot.RESULTS:LBP considerably strengthens cell viability and inhibits the apoptosis of RPE cells after photoinduction.The PI3K/Akt/mTOR signal pathway is activated because of the upregulation of the phosphorylation levels of Akt and mTOR proteins,and thus autophagy is inhibited.CONCLUSION:LBP can inhibit the excessive autophagy in RPE cells by activating the PI3K/Akt/mTOR signaling pathways and thereby protect RPE cells from photoinduced injuries.
文摘Cells have intrinsic mechanisms for cleaning harmful oxidants represented mainly by reactive oxygen species (ROS). Despite the antioxidant defense, ROS can cause serious damage to the retina that with age leads to various eye diseases and even blindness. Among numerous cell sites of ROS generation, mitochondrial electron transport is of crucial importance. Recently, for the purpose of cleaning ROS in the mitochondrial matrix, powerful mitochondria- targeted antioxidant “SkQ1” has been invented. We studied SkQ1 effects upon tissues of rat posterior eye cup that consisted: retinal pigment epithelium (RPE) ? choroidal coat ? scleral coat. The eye cups were isolated from the eyes of adult albino rats and cultivated in rotary tissue culture system in the presence of 20 nM SkQ1 or without this compound. After 7 days - 1 month in vitro eye cup samples were studied by immunohistochemistry, routine histology, morphometry, and digital image analysis. We have found that under chosen, “in vitro like in vivo” conditions 20 nM SkQ1 effectively reduced cell death in RPE and choroid, protected RPE from disintegration caused by cell phenotypic transformation and withdrawal from the layer, suppressed transmigration of choroidal coat cells. In the ex vivo model we used degenerative processes were more pronounced in the eye cup center where SkQ1 effect was most vivid. All this give us hopes for effectiveness of SkQ1 treatment of retinal central part that is very susceptible to light-induced over-oxidation injury and mostly suffering in many age-related diseases, AMD, in particular.
基金Supported by the National Natural Science Foundation of China(No.81271025No.81271023)
文摘AIM:To investigate the effect of Htr A1 on the proliferation,migration and apoptosis of human retinal pigment epithelium(RPE) cells in the light injured model,as well as the expression of the apoptosis related molecules.METHODS:The human RPE cell line ARPE-19 was exposed to blue light to establish the light injured model.The cells were transfected with Htr A1 si RNA to knockdown Htr A1 expression.Subsequent expression of Htr A1 was determined by real-time polymerase chain reaction(RTPCR) and Western blot,respectively.Changes in cell proliferation,migration and apoptosis were assessed by cell counting kit-8(CCK-8),Transwell assay and flow cytometry respectively,as well as changes in the m RNA and protein levels of Bax,Caspase-3 and Bcl-2 expression.RESULTS:Htr A1 was highly expressed in ARPE-19 cells after blue light irradiation.Knockdown of Htr A1 expression inhibited the proliferation,migration and apoptosis of the blue-light-irradiated ARPE-19 cells(P<0.05).Bax and Caspase-3 expression were significantly reduced both at m RNA and protein levels(P<0.05) after si RNA treatment.Bcl-2 expression significantly increased in blue-lightirradiated ARPE-19 cells after si RNA interference(P<0.05).CONCLUSION:Silence of Htr A1 may inhibit the proliferation,migration and apoptosis of ARPE-19 cells in light injured model.Moreover,Htr A1 suppression in blue-lightirradiated ARPE-19 cells may ameliorate cell apoptosis through down-regulation of Bax and Caspase-3,and upregulation of Bcl-2 expression.
基金Supported by the Natural Science Foundation of Shaanxi Province,China(No.2018JM7040)the Science and Technology Planned Projects of Xi’an City,China[No.20YXXJ008(4)]the Health Research Personnel Training Project of Xi’an Health Commission,China(No.J201901009)。
文摘AIM:To investigate YM155’s effect on retinal pigment epithelium(RPE)cells’viability and the potential regulatory mechanisms.METHODS:Human immortalized RPE cell lines(ARPE-19 cell line)were processed with YM155 and epidermal growth factor(EGF).ARPE-19 cell viability was detected by methyl thiazolyl tetrazolium assay,and apoptosis was tested by flow cytometry assay.ARPE-19 cell proliferation was assessed with bromodeoxyuridine tagged incorporation assay,and migration ability was evaluated via a wound-healing assay.Epidermal growth factor receptor(EGFR)/MAPK pathway proteins were tested via immunoblotting.EGFR localization was examined by immunofluorescence assay.RESULTS:YM155 suppressed ARPE-19 cells’viability in a time and concentration-dependent manner.A high dose of YM155 caused a small amount of ARPE-19 cell death.YM155 significantly diminished the ARPE-19 cells’proliferative and migrative capacity.YM155 downregulated total EGFR and phosphorylated external signalregulated protein kinase(ERK),and it up-regulated the phosphorylation of P38 MAPK and c-Jun N-terminal kinase(JNK).YM155 induced endocytosis of EGFR in ARPE-19 cell.YM155 also attenuated EGF-induced ARPE-19 cells’proliferative and migrative capacity.Moreover,YM155 significantly decreased the expression of phosphorylated EGFR and ERK after treated by EGF.CONCLUSION:YM155 inhibits RPE cell survival,the cell proliferative and migrative capacity,and it effectuates a small amount of cell death through the EGFR/MAPK signaling pathway.YM155 might,therefore,be an agent to prevent and treat abnormal RPE cell survival in proliferative vitreoretinopathy.
基金Supported by the National Natural Science Foundation of China(No.81700846)Tianjin Science and Technology Project of China(No.14JCYBJC27400)Science and technology Project of Tianjin Municipal Health Bureau(No.2015KZ073)
文摘AIM: To observe the effect of exosomes derived from human umbilical cord blood mesenchymal stem cells(h UCMSCs) on the expression of vascular endothelial growth factor-A(VEGF-A) in blue light injured human retinal pigment epithelial(RPE) cells and laser-induced choroidal neovascularization(CNV) in rats.METHODS: Exosomes were isolated from h UCMSCs and characterized by transmission electron microscope and Western blot. MSCs-derived exosomes were cultured with RPE cells exposed to blue light. The m RNA and protein expression of VEGF-A were determined by real time-polymerase chain reaction(PCR) and Western blot, respectively. Immunofluorescence assay was used for the detection of the expression level of VEGF-A. We injected different doses of MSCs-derived exosomes intravitreally to observe and compare their effects in a mouse model of laserinduced retinal injury. The histological structure of CNV in rats was inspected by hematoxylin-eosin(HE) staining and fundus fluorescein angiography. The expression of VEGF-A was detected by immunohistochemistry.RESULTS: Exosomes exhibited the typical characteristic morphology(cup-shaped) and size(diameter between 50 and 150 nm). The exosomes marker, CD63, and h UCMSCs marker, CD90, showed a robust presence. In vitro, MSCsderived exosomes downregulated the m RNA(Exo-L: t=6.485, 7.959, 9.286; Exo-M: t=7.517, 10.170, 13.413; Exo-H: t=10.317, 12.234, 14.592, P<0.05) and protein(Exo-L: t=2.945, 4.477, 6.657; Exo-M: t=4.713, 6.421, 8.836; Exo-H:t=6.539, 12.194, 12.783; P<0.05) expression of VEGF-A in RPE cells after blue light stimulation. In vivo, we found that the MSCs-derived exosomes reduced damage, distinctly downregulated VEGF-A(Exo-H: t=0.957, 1.382; P<0.05), and gradually improved the histological structures of CNV for a better visual function(Exo-L: 0.346, Exo-M: 3.382, Exo-H: 8.571; P<0.05). CONCLUSION: MSCs-derived exosomes ameliorate blue light stimulation in RPE cells and laser-induced retinal injury via downregulation of VEGF-A.
